Photo-sensitized Chemically Amplified Resist (PS-CAR) model calibration

ABSTRACT

Methods and systems for PS-CAR photoresist simulation are described. In an embodiment, a method includes calibrating initial conditions for a simulation of at least one process parameter of a lithography process using a radiation-sensitive material. In such an embodiment, the radiation-sensitive material includes a first light wavelength activation threshold that controls the generation of acid to a first acid concentration in the radiation-sensitive material and controls generation of photosensitizer molecules in the radiation-sensitive material, and a second light wavelength activation threshold that can excite the photosensitizer molecules in the radiation-sensitive material that results in the acid comprising a second acid concentration that is greater than the first acid concentration, the second light wavelength being different from the first light wavelength. Further, the method may include performing a lithography process using the previously-determined at least one process parameter.

BACKGROUND OF THE INVENTION

Field of Invention

The present invention relates to systems and methods for substrateprocessing, and more particularly to a method and system forPhoto-sensitized Chemically Amplified Resist (PS-CAR) model calibration.

Description of Related Art

In lithographic patterning of semiconductor devices, shrinkingtechnology nodes, and thus feature sizes are driving wavelengths intothe extreme ultraviolet (EUV) range. At this time, EUV light sources arestill under active development, and currently are not capable ofdeveloping and delivering the levels of illumination of priorgenerations of light sources. To address these shortcomings and still beable to utilize the current generation of EUV light sources, a resistchemistry and associated methods have been developed, calledPhoto-Sensitized Chemically-Amplified resist (PS-CAR). PS-CAR, liketraditional Chemically-Amplified resist (CAR), utilizes acid generatedwithin the resist feature for deprotection, but acid is generated in atwo-step illumination process, unlike CAR where only a single patternedexposure is used.

In PS-CAR, a first patterned exposure is used, often at EUV frequencies,to generate a pattern (latent image within the resist) with a relativelysmall amount of generated acid, and at the same time generate aphotosensitizer (PS) compound, for example from a photosensitizergenerator added to the PS-CAR resist. Both the acid and photosensitizer(PS) are generated only in illuminated portions of the PS-CAR resist,during the first patterned exposure. Thereafter, a flood exposure isperformed, i.e. with no pattern, at a second wavelength of lightdifferent than the wavelength of the first paterned exposure. The PS-CARresist chemistry is chosen such that the photosensitizer (PS) issensitive to the second wavelength of light used in the second floodexposure, while other resist components are not. The photosensitizer(PS), wherever present in the pattern formed during the first EUVpatterned exposure causes further generation of acid during the floodexposure, with tenfold increases of acid concentration, for example,being possible. This photosensitizer-induced acid concentration increaseresults in greatly increased contrast, which allows more processlatitude particularly with respect to the RLS tradeoff (Resolution—LineWidth Roughness—Sensitivity). Thus, PS-CAR presents an enablingtechnology for EUV lithography because it allows the productive use ofEUV sources and lithography at their present power levels.

It should be noted here that PS-CAR processes may involve additionalsteps, for example between the EUV patterned exposure and the floodexposure. The above description was simplified for purposes of clarity.Also, in some PS-CAR chemistry embodiments, no acid may be generatedduring the first EUV patterned exposure, and only photosensitizer may begenerated, which generated photosensitizer causes generation of all acidduring the flood exposure. Alternatively yet, acid may be generated insmall quantities, as explained before, but it may be effectivelyconsumed by competing chemical reactions, such as quenching events(depending on the amount of quencher present in the PS-CAR resist).

PS-CAR resist deposition, dosing, patterning, and developing may behighly sensitive processes in some embodiments. Due to the complexity ofPS-CAR resist chemistries, and the scale of patterned features, manyvariables may contribute to the quality of the resist mask, andtherefore, the resulting etched features. Resist patterning models havebeen used to predict resist layer and pattern qualities and to fine tuneresist processing parameters, however none of the traditional models aresuitable for patterning PS-CAR for a variety of reasons. First, PS-CARresist processing flows include additional steps which are not requiredin traditional CAR resist flows. Previous models do not account forthese additional flow steps. Second, PS-CAR resist is more sensitive toEUV and UV exposure dosing than traditional CAR resist, and prior modelsdo not account for such sensitivities. Third, traditional models aredesigned with preset parameters tuned to the chemistry of traditionalCAR chemistries, not for PS-CAR chemistries. One of ordinary skill willrecognize a variety of additional shortcomings of prior models used forsimulation traditional CAR resists.

SUMMARY OF THE INVENTION

Methods and systems for PS-CAR photoresist simulation are described. Inan embodiment, a method includes calibrating initial conditions for asimulation of at least one process parameter of a lithography processusing a radiation-sensitive material. In such an embodiment, theradiation-sensitive material includes a first light wavelengthactivation threshold that controls the generation of acid to a firstacid concentration in the radiation-sensitive material and controlsgeneration of photosensitizer molecules in the radiation-sensitivematerial, and a second light wavelength activation threshold that canexcite the photosensitizer molecules in the radiation-sensitive materialthat results in the acid comprising a second acid concentration that isgreater than the first acid concentration, the second light wavelengthbeing different from the first light wavelength. Further, the method mayinclude performing a lithography process using the previously-determinedat least one process parameter.

Another embodiment of a method includes receiving, at an inputinterface, a physical parameter of a radiation-sensitive material foruse in the lithography process. The method may also include receiving,at the input interface, an exposure parameter associated with at leastone of a first radiation exposure step and a second radiation exposurestep of the lithography process. Additionally, the method may includecalculating, using a data processor, a profile of theradiation-sensitive material according to a lithography process model,and in response to the physical parameter and the radiation exposureparameter. In an embodiment, the method may include receiving, at theinput interface, feedback indicative of an error value corresponding toa comparison of the profile of the radiation-sensitive material and anexperimental verification of the model. Further, the method may includeoptimizing, using the data processor, at least one of the physicalparameter and the exposure parameter in response to the feedback.Additionally, the method may include generating an output, at an outputinterface, comprising at least one of the optimized physical parameterand the optimized exposure parameter in response to a determination thatthe error value is within a threshold margin of error.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the invention and,together with the general description of the invention given above, andthe detailed description given below, serve to describe the invention.

FIG. 1 is an embodiment of a semiconductor wafer processing system.

FIG. 2A shows an embodiment of photosensitizer and acid concentrationprofiles following an EUV patterned exposure step in a PS-CAR patterningprocess

FIG. 2B shows a device cross section following an EUV patterned exposurestep in a PS-CAR patterning process.

FIG. 2C shows photosensitizer and acid concentration profiles followinga flood exposure step in a PS-CAR patterning process.

FIG. 2D shows a device cross section following a flood exposure step ina PS-CAR patterning process.

FIG. 3A shows photosensitizer and acid concentration profiles prior to aflood exposure step, with illustrated effects of unmitigated EUV shotnoise in a PS-CAR patterning process.

FIG. 3B shows photosensitizer and acid concentration profiles followinga flood exposure step, with illustrated effects of unmitigated EUV shotnoise in a PS-CAR patterning process.

FIG. 3C shows photosensitizer concentration profiles prior to an EUVshot noise mitigation step, and an acid concentration profile followingthe EUV shot noise mitigation step in a PS-CAR patterning process inaccordance with an embodiment of the invention.

FIG. 3D shows exemplary acid concentration profiles following the EUVshot noise mitigation step and following a flood exposure step in aPS-CAR patterning process in accordance with an embodiment of theinvention

FIG. 4 shows a process flow for a PS-CAR patterning process inaccordance with an embodiment of the invention.

FIG. 5 is a schematic block diagram illustrating one embodiment of adata processing system configured for PS-CAR photoresist simulation.

FIG. 6 is a schematic block diagram illustrating one embodiment of asystem for PS-CAR photoresist simulation.

FIG. 7 is a schematic flowchart diagram illustrating one embodiment of amethod for calibrating input parameters of a PS-CAR photoresist model.

FIG. 8 is a schematic flowchart diagram illustrating one embodiment of amethod for calibrating input parameters of a PS-CAR photoresist model.

FIG. 9 is a schematic flowchart diagram illustrating one embodiment of amethod for simulating PS-CAR photoresist.

FIG. 10 is a schematic flowchart diagram illustrating one embodiment ofa method for simulating PS-CAR photoresist.

FIG. 11 is a schematic input/output diagram illustrating an embodimentof an input/output data set for a PS-CAR photoresist model.

FIG. 12 is a schematic parameter architecture diagram illustrating oneembodiment of an input data set for a PS-CAR photoresist model.

FIG. 13 is a schematic parameter architecture diagram illustrating oneembodiment of an output data set for a PS-CAR photoresist model.

FIG. 14 is a schematic parameter architecture diagram illustratingoperation of one embodiment of a EUV Optics module of a PS-CARphotoresist model.

FIG. 15 is a schematic parameter architecture diagram illustratingoperation of one embodiment of a EUV exposure module of a PS-CARphotoresist model.

FIG. 16 is a schematic parameter architecture diagram illustratingoperation of one embodiment of a pre-PEB module of a PS-CAR photoresistmodel.

FIG. 17 is a schematic parameter architecture diagram illustratingoperation of one embodiment of a UV optics simulator of a PS-CARphotoresist model.

FIG. 18 is a schematic parameter architecture diagram illustratingoperation of one embodiment of a UV flood exposure module of a PS-CARphotoresist model.

FIG. 19 is a schematic parameter architecture diagram illustratingoperation of one embodiment of a PEB module of a PS-CAR photoresistmodel.

FIG. 20 is a schematic parameter architecture diagram illustratingoperation of one embodiment of a developer module of a PS-CARphotoresist model.

FIG. 21 is a schematic parameter architecture diagram illustratingoperation of one embodiment of a metrology module of a PS-CARphotoresist model.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Embodiments of the present invention relate to design and control of aprocess, apparatus, and system for patterning a layer on a substrate, insemiconductor manufacturing.

In the following description, in order to facilitate a thoroughunderstanding of the invention and for purposes of explanation and notlimitation, specific details are set forth, such as particulargeometries of a mask, coater/developer, exposure tools, and descriptionsof various components and processes. However, it should be understoodthat the invention may be practiced in other embodiments that departfrom these specific details.

In the description to follow, the terms radiation-sensitive material andphotoresist may be used interchangeably, photoresist being only one ofmany suitable radiation-sensitive materials for use in photolithography.Similarly, hereinafter the term substrate, which represents theworkpiece being processed, may be used interchangeably with terms suchas semiconductor wafer, LCD panel, light-emitting diode (LED),photovoltaic (PV) device panel, etc., the processing of all of whichfalls within the scope of the claimed invention.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure, material, orcharacteristic described in connection with the embodiment is includedin at least one embodiment of the invention, but do not denote that theyare present in every embodiment. Thus, the appearances of the phrases“in one embodiment” or “in an embodiment” in various places throughoutthis specification are not necessarily referring to the same embodimentof the invention. Furthermore, the particular features, structures,materials, or characteristics may be combined in any suitable manner inone or more embodiments.

Various operations will be described as multiple discrete operations inturn, in a manner that is most helpful in understanding the invention.However, the order of description should not be construed as to implythat these operations are necessarily order dependent. In particular,these operations need not be performed in the order of presentation.Operations described may be performed in a different order than thedescribed embodiment. Various additional operations may be performedand/or described operations may be omitted in additional embodiments.

Furthermore, the use of photo-sensitized chemically-amplified resist(PS-CAR) is not limited only to resist (photoresist), but similarlight-sensitive chemistries can be implemented in antireflectivecoatings (ARC), bottom antireflective coatings (BARC), developer-solublebottom antireflective coatings (DBARC), overcoat materials, smart slimmaterials, etc. It is understood that the PS-CAR chemistries and methodsdescribed herein may be applied to all these materials and patterningthereof, and therefore the terms resist, photoresist, andradiation-sensitive material will be used interchangeably hereinafter torefer to all of these materials.

The photo-sensitized chemically-amplified resist (PS-CAR) concept isdescribed in some detail below. In contrast to traditional resistprocessing wherein a single patterned exposure (i.e. through a mask)generates regions of de-protected (positive-tone) or protected(negative-tone) resist that define soluble and insoluble regions,respectively, PS-CAR processing relies on a first patterned exposure ata first wavelength of light to amplify sensitivity of the resist to asecond chemically-selective flood exposure at a second wavelength oflight, which defines the final pattern. The second wavelength of lightis chosen to be different than the first wavelength of light. Thisenables higher sensitivity patterning when photon density is low. Thephotosensitizer (PS) is created during the first EUV patterned exposure,and only in exposed regions of the resist. Electron beam (eBeam), KrF,or ArF exposure can also be used for the first patterned exposure.

The choice of flood exposure wavelength is dictated by the requirementthat the absorption by the photosensitizer (PS) be maximized whileminimizing the absorbance by the photo acid generator (PAG) or the PSgenerator in the resist. Typically, the flood exposure wavelength oflight is in the UV portion of the light spectrum. The photosensitizer(PS) excited by the second flood exposure will decompose photoacidgenerator (PAG) molecules in its vicinity causing amplification of acidgeneration in regions that were exposed in the first EUV patternedexposure, while essentially maintaining no acid formation in unexposedregions. This means there is no DC-bias shift that is typically presentin traditional flood exposure processes.

The resist thus may include a separate activation thresholds thatenables the generation of chemicals within the resist to occur atdifferent times under different process conditions, prior to beingdeveloped. Specifically, the concept is to isolate the generation ofphotosensitizer (PS) and acid amplification from one another, within theresist. In some PS-CAR chemistry embodiments, only the photosensitizerand no acid are generated during the first EUV patterned exposure, theacid generation and amplification occurring entirely during thesubsequent second flood exposure. In these embodiments, there is nooverlap in the light sensitivity ranges of the photosensitizer generatorand the photoacid generator (PAG). In other PS-CAR chemistryembodiments, the photosensitizer generator and photoacid generator (PAG)light sensitivity ranges may overlap slightly, such that photosensitizer(PS) is generated concurrently with a relatively small amount of acid,typically less than about half of the final amount of generated acidafter amplification, during the first EUV patterned exposure. Thisinitially generated amount of acid is then amplified in the second floodexposure. In exemplary embodiments of PS-CAR, the first (EUV) wavelengthof light may be less than 300 nm while the second wavelength of lightused for second flood exposure may be greater than 300 nm, typicallyabout 365 nm.

In an embodiment, the resist may include a photosensitizer generatorcomprising a first light wavelength activation threshold that controlsgeneration of photosensitizer (PS) molecules in the resist layer and aphotoacid generation (PAG) compound comprising a second light wavelengthactivation threshold that controls the generation and amplification ofacid in the resist layer, wherein the second activation wavelength isdifferent than the first activation wavelength, as mentioned before. Thephotosensitizer molecule may be chosen to absorb light energy andtransfer the light energy to another molecule, for example a photoacidgenerator (PAG). Some photosensitizer (PS) molecules may transfer energyin a ground state while other may transfer energy in an excited state.In an embodiment, the photosensitizer generator of PS-CAR resist maycomprise at least one of acetophenone, triphenylene, benzophenone,flourenone, anthraquinone, phenanthrene, or derivatives thereof. In anembodiment, the photoacid generator (PAG) may be a cationicphotoinitiator that may convert absorbed light energy into chemicalenergy, for example an acidic reation. The photoacid generator (PAG) maycomprise at least one of triphenylsulfonium triflate, triphenylsulfoniumnonaflate, triphenylsulfonium perfluorooctylsulfonate, triarylsulfoniumtriflate, triarylsulfonium nonaflate, triarylsulfoniumperfluorooctylsulfonate, a triphenylsulfonium salt, a triarylsulfoniumsalt, a triarylsulfonium hexafluoroantimonate salt,N-hydroxynaphthalimide triflate,1,1-bis[p-chlorophenyl]-2,2,2-trichloroethane(DDT),1,1-bis[p-methoxyphenyl]-2,2,2-trichloroethane,1,2,5,6,9,10-hexabromocyclododecane, 1,10-dibromodecane,1,1-bis[p-chlorophenyl]2,2-dichloroethane,4,4-dichloro-2-(trichloromethyl)benzhydrol, 1,1-bis(chlorophenyl)2-2,2-trichloroethanol, hexachlorodimethylsulfone,2-chloro-6-(trichloromethyl)pyridine, or derivatives thereof.

FIG. 1 is an embodiment of a semiconductor wafer processing system 100.In an embodiment, a semiconductor substrate 102, such as a siliconwafer, is inserted into a PS-CAR photoresist coating unit 104. Thesemiconductor substrate 102 may then be coated with one or more layersof PS-CAR photoresist. The substrate 102 may then be passed to a patternexposure unit 106, such as a EUV exposure unit, for patterning of thePS-CAR photoresist layer. After patterning, the substrate 102 may beexposed to a second wavelength of light, such as a flood of UV light inthe flood exposure unit 108 for further development of the PS-CARphotosensitizer and other acid-generating components of the PS-CARchemistry. The substrate 102 may then be passed to a pattern etch unit110 for patterned etching of one or more layers on the substrate asdefined by the PS-CAR photoresist patterned mask. The resultingsubstrate 102 may include one or more physical features 112 formedtherein, or in one or more layers deposited on the substrate 102. One ofordinary skill will recognize that additional steps and/or functionalunits may be included in system 100. For example, the wafer 102 may beplaced in proximity to a heating element for Post Exposure Bake (PEB) orfor a pre-PEB diffusion process. Additionally, one or more portions ofthe PS-CAR photoresist layer may be removed prior to etching in a wetetch processing chamber, a cleaning chamber, or a photoresist selectivedry etch chamber. Additionally, the PS-CAR layer(s) may be developed ina dedicated developer unit, or the like. These additional modules orunits have not been illustrated in order to simplify the discussion ofthe technologies presented herein. These additional details will beknown to one of ordinary skill in the art.

To further assist understanding, FIGS. 2A-D describe the PS-CARpatterning process prior to subsequent development and etching steps. InFIG. 2B, a substrate 250 is provided that is coated or modified to forman underlying layer 260, which is to be patterned. A PS-CAR resist 270is applied using, for example, spin-on dispense techniques, to theexposed surface of the underlying layer 260. In the first EUV patternedexposure 201, a first wavelength of light 290 is exposed onto the PS-CARresist 270 through a mask 280, to form alternating exposed and unexposedregions inside PS-CAR resist 270. During this exposure, photosensitizer(PS) is generated from the photosensitizer generator in exposed regionsof the PS-CAR resist 270, to form photosensitizer (PS) concentrationprofiles 220, which are also shown enlarged in FIG. 2A with graphs 200of photosensitizer (PS) and acid concentrations, 220 and 210,respectively. Depending on the PS-CAR resist chemistry, in someembodiments, acid may also be formed during first EUV patterned exposure101 from photoacid generators (PAG) molecules inside PS-CAR resist 270,to form acid concentration profiles 210. In other embodiments, wherethere is no overlap between photosensitizer generator and photoacidgenerator (PAG) light sensitivity ranges, as described before, no acidis generated during the first EUV patterned exposure 201.

Subsequently, as shown in FIG. 2D, the substrate 250, with underlyinglayer 260 and pattern-exposed PS-CAR resist 270 is now subjected to asecond flood exposure 201 using a second wavelength of light 290different than the first wavelength of light 290, where the second floodexposure causes photosensitizer (PS) molecules generated in previouslyexposed (i.e. unmasked) regions to amplify acid generation fromphotoacid generator (PAG) molecules in their vicinity, thereby formingacid concentration profiles 210. Acid concentration profiles 210 havehigher peaks and therefore a better contrast than acid concentrationprofiles 210 following the first EUV patterned exposure 201. Even thougha second flood exposure 201 is involved, unlike in traditional floodexposure processing there is no generation of acid in regions that wereunexposed (masked) during the first EUV patterned exposure 201, thusthere is no DC-bias and a high contrast is maintained. This is becausein PS-CAR acid generation and amplification occur only in the presenceof photosensitizer (PS). Typically, photosensitizer (PS) concentrationprofiles 220 undergo little change after second flood exposure 201 frominitial photosensitizer (PS) concentration profiles 220, but in certainchemistry embodiments, larger changes may occur between photosensitizer(PS) concentrations 220 and 210. FIG. 2C shows graphs 200 ofphotosensitizer (PS) and acid concentration profiles, 220 and 210,respectively, following the second flood exposure 201.

With the amplified acid concentration profiles 210 now present in thePS-CAR resist 270, forming a latent image, the substrate is now readyfor subsequent patterning process steps, such as bakes, development, andetching of the underlying layer 260, to complete the patterning processfollowing traditional steps. In some embodiments, additional processingsteps may be made between the first EUV patterned exposure 201 andsecond flood exposure 201, such as baking steps, etc. Furthermore, whilethe process is described herein using PS-CAR resist 270 as an example,the same process is applicable to any other materials such as ARC, BARC,DBARC, overcoat materials, etc. layers including a PS-CAR chemistry.

FIGS. 2A-2D showed what ideal photosensitizer (PS) and acidconcentration profiles may look like. FIG. 3A shows an exemplaryphotosensitizer (PS) concentration profile 320 and an acid concentrationprofile 310 with effects of EUV shot noise accrued during the first EUVpatterned exposure 201. EUV shot noise causes a departure from idealconcentration profiles 210 and 220, respectively, of FIG. 2A. If suchnon-ideal photosensitizer (PS) concentration profile 320 and an acidconcentration profile 310 are now subjected to a second flood exposure201, the second flood exposure 201 may amplify the irregularities of theacid concentration profile 310 into a final acid concentration profile315, with loss of contrast, as shown in FIG. 3B. The loss of contrast inacid concentration profile 315 is a major contributor to line widthroughness (LWR) in patterning (or LER or CER, depending on device type),and measures to mitigate this loss of contrast due to EUV shot noise arerequired to maintain pattern integrity.

The inventors have conceived of a number of possible ways to mitigatethis loss of contrast due to EUV shot noise. Most of these methods arebased on including an intermediate step between the first EUV patternedexposure 201 and the second flood exposure 201, in which the generatedphotosensitizer (PS) is allowed to diffuse within its vicinity, tosmooth out the irregularities caused by EUV shot noise.

FIG. 3C shows graphs of photosensitizer (PS) concentration profile 320prior to and photosensitizer (PS) concentration profile 325 followingthe photosensitizer diffusion step. The photosensitizer (PS)concentration profile 325 is smoother that the EUV shot-noise-affectedphotosensitizer (PS) concentration profile 320, and should greatlyreduce deviations from ideal of the final acid concentration profile.The acid concentration profile 335 after diffusion of photosensitizer(PS) is also shown in FIG. 3C. With the diffused and smoothedphotosensitizer (PS) concentration profile 325, the process proceedswith the second flood exposure to generate and amplify the acid. Duringthis process, a final acid concentration profile 340 is reached, asshown in FIG. 3D, which is much improved over the concentration profile315 of FIG. 3B which is obtained without steps to mitigate EUV shotnoise.

With reference now to FIG. 4, therein is shown a flowchart 400 of aPS-CAR patterning process with EUV shot noise mitigation. In step 402, asubstrate is provided, such as substrate 250 with underlying layer 260to be patterned formed thereupon, and a PS-CAR resist 170 deposited atopthe underlying layer 260. In step 404, the PS-CAR resist is subjected toa first EUV patterned exposure using a first wavelength of light,typically in the EUV range, thus activating the first activationthreshold to generate photosensitizer (PS) from photosensitizergenerator present in the PS-CAR resist 270. In step 406, the generatedphotosensitizer (PS) molecules are allowed to diffuse to mitigateeffects of EUV shot noise. In step 408, the PS-CAR resist 270 issubjected to a second flood exposure at a second wavelength of lightdifferent than the first wavelength of light, to activate a secondactivation threshold and cause generation and amplification of acid fromphotoacid generator (PAG) molecules in the PS-CAR resist 270, togenerate a final acid concentration profile corrected for effects of EUVshot noise, as explained before.

With continued reference to FIG. 4, further patterning steps may includetraditional patterning steps, such as an subsequent bake process 410during which the substrate is heated, followed by a development process412 in which the PS-CAR resist 270 is developed to form a patterned maskfor subsequent processing of the underlying layer 260. Lastly, theprocess concludes at the actual process 414 in which the underlyinglayer 260 is etched, implanted, or modified using developed PS-CARresist as a mask. All these processes are well known to those skilled inthe art of semiconductor lithographic patterning, and will thus not bediscussed in detail herein.

In the simplest embodiment, allowing sufficient time between the firstEUV patterned exposure and the second flood exposure for the generatedphotosensitizer (PS) molecules to diffuse represents the simplestembodiment of the step 406 of diffusing photosensitizer (PS) molecules.However, this approach may cause a processing throughput penalty becauseof substrates held between exposures to allow diffusion to take place.

FIG. 5 is a schematic block diagram illustrating one embodiment of adata processing system 500 configured for PS-CAR photoresist simulation.In one embodiment, elements illustrated in FIG. 6 may be implemented ona computer system similar to the computer system 500 described in FIG.5. In various embodiments, computer system 500 may be a server, amainframe computer system, a workstation, a network computer, a desktopcomputer, a laptop, or the like. While the present embodiments are notlimited to any specific computing platform, or any specific computerconfiguration, one of ordinary skill will recognize that the systemshould include sufficient computational and processing power, as well assufficient memory to accommodate many simultaneous calculationsassociated with the simulation performed as described herein.

For example, as illustrated, computer system 500 includes one or moreprocessors 502A-N coupled to a system memory 504 via bus 506. Computersystem 500 further includes network interface 508 coupled to bus 506,and input/output (I/O) controller(s) 510, coupled to devices such ascursor control device 512, keyboard 514, and display(s) 516. In someembodiments, a given entity (e.g., the PS-CAR simulation toolillustrated in FIG. 6) may be implemented using a single instance ofcomputer system 500, while in other embodiments multiple such systems,or multiple nodes making up computer system 500, may be configured tohost different portions or instances of embodiments (e.g., calibrationunit 602 and PS-CAR simulation tool 604).

In various embodiments, computer system 500 may be a single-processorsystem including one processor 502A, or a multi-processor systemincluding two or more processors 502A-N (e.g., two, four, eight, oranother suitable number). Processor(s) 502A-N may be any processorcapable of executing program instructions and executing quantitativelyintensive calculations. For example, in various embodiments,processor(s) 502A-N may be general-purpose or embedded processorsimplementing any of a variety of instruction set architectures (ISAs),such as the x86, POWERPC®, ARM®, SPARC®, or MIPS® ISAs, or any othersuitable ISA. In multi-processor systems, each of processor(s) 502A-Nmay commonly, but not necessarily, implement the same ISA. Also, in someembodiments, at least one processor(s) 502A-N may be a graphicsprocessing unit (GPU) or other dedicated graphics-rendering device.

System memory 504 may be configured to store program instructions and/ordata accessible by processor(s) 502A-N. For example, memory 504 may beused to store software program and/or database shown in FIGS. 7-10. Invarious embodiments, system memory 504 may be implemented using anysuitable memory technology, such as static random access memory (SRAM),synchronous dynamic RAM (SDRAM), nonvolatile/Flash-type memory, or anyother type of memory. As illustrated, program instructions and dataimplementing certain operations, such as, for example, those describedabove, may be stored within system memory 504 as program instructions518 and data storage 520, respectively. In other embodiments, programinstructions and/or data may be received, sent or stored upon differenttypes of computer-accessible media or on similar media separate fromsystem memory 504 or computer system 500. Generally speaking, acomputer-accessible medium may include any tangible, non-transitorystorage media or memory media such as electronic, magnetic, or opticalmedia—e.g., disk or CD/DVD-ROM coupled to computer system 500 via bus506, or non-volatile memory storage (e.g., “flash” memory)

In an embodiment, bus 506 may be configured to coordinate I/O trafficbetween processor 502, system memory 504, and any peripheral devicesincluding network interface 508 or other peripheral interfaces,connected via I/O controller(s) 510. In some embodiments, bus 506 mayperform any necessary protocol, timing or other data transformations toconvert data signals from one component (e.g., system memory 504) into aformat suitable for use by another component (e.g., processor(s)502A-N). In some embodiments, bus 506 may include support for devicesattached through various types of peripheral buses, such as a variant ofthe Peripheral Component Interconnect (PCI) bus standard or theUniversal Serial Bus (USB) standard, for example. In some embodiments,the operations of bus 506 may be split into two or more separatecomponents, such as a north bridge and a south bridge, for example. Inaddition, in some embodiments some or all of the operations of bus 506,such as an interface to system memory 504, may be incorporated directlyinto processor(s) 502A-N.

Network interface 508 may be configured to allow data to be exchangedbetween computer system 500 and other devices, such as other computersystems attached to the PS-CAR simulation tool as shown in FIG. 6, forexample. In various embodiments, network interface 508 may supportcommunication via wired or wireless general data networks, such as anysuitable type of Ethernet network, for example; viatelecommunications/telephony networks such as analog voice networks ordigital fiber communications networks; via storage area networks such asFiber Channel SANs, or via any other suitable type of network and/orprotocol.

I/O controller(s) 510 may, in some embodiments, enable connection to oneor more display terminals, keyboards, keypads, touch screens, scanningdevices, voice or optical recognition devices, or any other devicessuitable for entering or retrieving data by one or more computer system500. Multiple input/output devices may be present in computer system 500or may be distributed on various nodes of computer system 500. In someembodiments, similar I/O devices may be separate from computer system500 and may interact with computer system 500 through a wired orwireless connection, such as over network interface 508.

The terms “tangible” and “non-transitory,” as used herein, are intendedto describe a computer-readable storage medium (or “memory”) excludingpropagating electromagnetic signals; but are not intended to otherwiselimit the type of physical computer-readable storage device that isencompassed by the phrase computer-readable medium or memory. Forinstance, the terms “non-transitory computer readable medium” or“tangible memory” are intended to encompass types of storage devicesthat do not necessarily store information permanently, including, forexample, RAM. Program instructions and data stored on a tangiblecomputer-accessible storage medium in non-transitory form may afterwardsbe transmitted by transmission media or signals such as electrical,electromagnetic, or digital signals, which may be conveyed via acommunication medium such as a network and/or a wireless link.

As shown in FIG. 5, memory 504 may include program instructions 518,configured to implement certain embodiments described herein, and datastorage 520, comprising various data accessible by program instructions518. In an embodiment, program instructions 518 may include softwareelements of embodiments illustrated in FIG. 6. For example, programinstructions 518 may be implemented in various embodiments using anydesired programming language, scripting language, or combination ofprogramming languages and/or scripting languages. Data storage 520 mayinclude data that may be used in these embodiments such as, for example,input parameters, mid-stream calculation values, or output parameters,as illustrated in FIGS. 11-20. In other embodiments, other or differentsoftware elements and data may be included.

A person of ordinary skill in the art will appreciate that computersystem 500 is merely illustrative and is not intended to limit the scopeof the disclosure described herein. In particular, the computer systemand devices may include any combination of hardware or software that canperform the indicated operations. In addition, the operations performedby the illustrated components may, in some embodiments, be performed byfewer components or distributed across additional components. Similarly,in other embodiments, the operations of some of the illustratedcomponents may not be performed and/or other additional operations maybe available. Accordingly, systems and methods described herein may beimplemented or executed with other computer system configurations.

FIG. 6 is a schematic block diagram illustrating one embodiment of asystem 600 for PS-CAR photoresist simulation. In an embodiment, thesystem 600 includes a calibration unit 602 and a PS-CAR simulation tool604. The calibration unit 602 may generate one or more input parametersspecific to the PS-CAR chemistry to be modeled by the PS-CAR simulationtool 604. In an embodiment, the calibration unit 602 may be configuredto perform operations associated with one or more of the embodiments ofa method described in FIGS. 7-8.

The PS-CAR simulation tool 604 may receive the input parametersgenerated by the calibration unit, and other input parameters specificto the PS-CAR photoresist to be used, the system and processingparameters, as well as the specific features to be patterned. Inresponse to the received inputs, the PS-CAR simulation tool 604 maycompute a numerical model that is representative of the PS-CARprocessing methods to be used, for example, by the system 100 describedin FIG. 1. In general, the PS-CAR simulation tool 604 may be configuredto carry out operations described in the methods of FIGS. 9-10. Asdescribed above, the various modules or units of the calibration unit602 and the PS-CAR simulation tool may be software-defined modulesstored in a memory device and configured to be executed by one or moreprocessing devices, such as those illustrated in FIG. 5.

In an embodiment, the input interface 606 may be configured to receiveinput parameters, and other controls and commands for generatingoptimized inputs for the PS-CAR simulation tool 604. Examples of inputsmay include optical parameters of the photoresist, such as refractiveindex, Dill A, and Dill B parameters, etc. Additional input parametersmay include acid generation and bake parameters, such as, Dill C,quencher loading, amplification parameters, acid/base quench parameters,and acid/base diffusion parameters. Further, develop parameters may bereceived, including for example, development rate (Rmax/Rmin)parameters, etc. One of ordinary skill will recognize that the inputsmay be initial conditions for these, and other parameters.Alternatively, inputs received by the input interface 606 may includefeedback from physical measurements of verification experiments, and thelike.

In an embodiment, the photoresist profile processor 608 may calculate anestimate of the physical features of the photoresist layer in responseto the received inputs. For example, the photoresist profile processormay calculate a model of photoresist layer thicknesses, patternfeatures, such as edge sharpness, shot noise, etc., thickness lost, andthe like. Further, the photoresist profile processor 608 may determine anumber acid generators, quenchers (photo-decomposable quenchers or moretraditional non photo-decomposable quenchers), precursors(photosensitizer generators), and photosensitizers within a photoresistvolume.

The photoresist profile processor 608 may be further configured toperform one or more of the following operations: determine a number ofacid induced de-protection reactions of the precursor to convert it tophotosensitizer, determine the number of photons of primary exposure orsecondary mid-UV flood absorbed by the photoresist volume, determine thenumber of the acid generators converted to acid by primary exposure orby photosensitizer activation by secondary mid-UV exposure wavelength,or range of wavelengths, and subsequent acid generator decomposition byexcited photosensitizer, determine the number of the photo-decomposablequenchers (if applicable) decomposed by primary exposure or by secondarymid-UV exposure wavelength, or range of wavelengths, determine a numberof acid and quencher neutralization reactions within the photoresistvolume, determine the number of acid induced de-protection reactions ofthe protected polymer, calculate a development of the photoresistvolume, produce with the processor a two-dimensional (orthree-dimensional) image of the photoresist profile created by thedevelopment of the photoresist volume, and determine the dimensionalproperties of the photoresist profile. One of ordinary skill willrecognize that these are merely a selection of the calculations whichmay be performed by the photoresist profile processor 608.

In an embodiment, the parameters calculated by the photoresist profileprocessor 608 may be provided to the PS-CAR simulation tool 604 via theoutput interface 612. In another embodiment, the output interface 612may provide a readout, or printout of the calculated parameters forexperimental verification. In response, engineers or scientists mayexperimentally verify the calculated parameters by conducting an actuallithography process with the selected PS-CAR chemistry according to theprocessing parameters, including exposure wavelength and dosing time,photoresist deposition rate, wafer turn rate, PEB specifications, etc.The actual dimensions of the experimentally developed wafer are thenphysically measured and compared with the model results. The differencesbetween the modeled and actual results are provided to the inputinterface 606 as feedback for the optimization engine 610.

The optimization engine 610 may use one or more optimization algorithms,such as a gradient approach algorithm, a simplex algorithm, asemi-stochastic simulated annealing algorithm, a genetic algorithm, orothers to modify the input parameters in order to reduce or eliminateerror between the modeled results and the actual experimental results.In general, the error feedback will be assigned a numerical value, whichmay have a directional sign, for pulling or pushing the input parameterstoward values that generate a global minimum of error between themodeled and actual results.

In some embodiments, the optimization engine 610 may optimize PS-CARoptical parameters as described above. Further, the optimization engine610 may optimize acid generation and bake parameters. In still a furtherembodiment, the optimization engine 610 may optimize develop parameters.In some embodiments, these three categories of parameters may beoptimized independently and in series. Alternatively, the categories maybe optimized independently and in parallel. Alternatively, thecategories may be optimized dependently and in series, or dependentlyand in parallel. Examples of these optimization techniques areillustrated in FIG. 8.

Once the difference between the actual photoresist features and themodeled features reaches a threshold value, the optimization engine 610may terminate the optimization process and the optimized parameters maybe provided to the PS-CAR simulation tool 604 via the output interface612. One of ordinary skill will recognize that the input interface 606and the output interface may be hardware-based input/output interfaces.Alternatively, the input interface 606 and the output interface 612 maybe software-defined, and the inputs and outputs may be passed betweenfunctions or modules of the software as function call parameters orfunction return values.

In addition to the calibrated parameters provided by the calibrationunit 602, the PS-CAR simulation tool 604 may receive one or moreprocess-specific parameters for an actual process to be modeled. ThePS-CAR simulation tool 604 may include a plurality of modules or units,each unit configured to perform a portion of the model calculationsassociated with a processing step. The units may include an primaryexposure patterning optics unit 614, an primary exposure patterning unit616, a pre-PEB unit 618, a secondary exposure patterning unit 620, asecondary exposure unit 622, a PEB unit 624, a develop unit 626, and ametrology unit 628. The modules may execute a continuum model.Alternatively, the modules may execute a partially stochastic model. Oneof ordinary skill will recognize alternative embodiments.

In an embodiment, the primary exposure patterning optics unit 614 mayinclude a simulated EUV source. The simulator may simulate acommercially available optical source used for patterning the PS-CARphotoresist layer. Additional parameters may include intensity, focuslength, etc. Further details of the primary exposure patterning opticsunit 614 are illustrated in FIG. 14.

In an embodiment, the EUV unit 616 is configured to model the responsein the PS-CAR photoresist layer in response to EUV exposure from thesimulated EUV source. Modeled parameters may include one or more of:exposure time/dose, mask feature sizes, stepper/scanner settings, focus,polarization, etc. Further details of the primary exposure patterningunit 616 are illustrated in FIG. 15.

In an embodiment, the Pre-PEB unit 618 may model the results of apre-PEB photosensitizer diffusion process. The pre-PEB unit 618 may beoptional in some embodiments, or at least selectably employed inresponse to a pre-PEB diffusion period. Further details of the pre-PEBunit 618 are illustrated in FIG. 16.

In an embodiment, the secondary optics unit 620 may be configured tosimulate a commercially available UV source. The secondary optics unit620 may model the wavelength, intensity, illumination method, etc. Thesecondary optics unit 620 may be used by the UV flood unit 622 to modelthe physical results of the UV flood process on the PS-CAR photoresistlayer. Further details of the secondary optics unit 620 and the UV floodunit 622 are illustrated in FIGS. 17-18 respectively.

In an embodiment, the PEB unit 624 may model the response of thephotoresist to a post-exposure bake process. Modeled parameters mayinclude bake temperature, bake time, bake humidity, etc. further detailsof the PEB unit 624 are described in FIG. 19.

In an embodiment, the develop unit 626 may be configured to model theresponse of the PS-CAR photoresist to a develop process. Modeledparameters may include relative surface rate, inhibition depth, andother develop conditions. Further details of the parameters modeled bythe develop unit 626 are illustrated in FIG. 20.

In an embodiment, the metrology unit 628 is configured to providesimulated measurement values of modeled features on the PS-CARphotoresist layer. The measurement values may include resist loss,deprotection levels and profiles, etc. In some embodiments, continuummodel outputs may be provided. In alternative embodiments, stochasticmodel outputs may be provided. Further details of the parameters modeledby the metrology unit 628 are illustrated in FIG. 21.

FIG. 7 is a schematic flowchart diagram illustrating one embodiment of amethod 700 for calibrating input parameters of a PS-CAR photoresistmodel. In an embodiment, the method 700 may include receiving one ormore PS-CAR photoresist parameters at block 702. Exposure parameters maybe received at block 704. The method 700 may include computing a PS-CARphotoresist profile in response to the received PS-CAR photoresistparameters and the received exposure parameters at block 706. At block708, the method 700 may include receiving feedback from an experimentalverification of the PS-CAR photoresist profile. If, at block 710, it isdetermined that the error is within a threshold margin, then theoptimized parameters are provided as input into a PS-CAR simulation toolat block 716. If not, the PS-CAR photoresist parameters and the exposureparameters may optionally be optimized at blocks 712 and 714respectively. The optimization loop may continue until the threshold ismet at block 710.

The flowcharts illustrated in FIGS. 7-10 illustrate methods forcalculating a PS-CAR photoresist profile. FIGS. 7-8 are directed tomethods for calibrating model parameters, and FIGS. 9-10 are directed tomethods for calculating a PS-CAR photoresist profile according to aPS-CAR photoresist model.

FIG. 8 is a schematic flowchart diagram illustrating one embodiment of amethod 800 for calibrating input parameters of a PS-CAR photoresistmodel. In an embodiment, the method 800 includes receiving PS-CARparameters at block 802. The optical parameters may be optimized inresponse to feedback from experimental verification at block 804 untilthe threshold is reached at block 806. The acid generation and bakeparameters may be optimized in response to the feedback fromexperimental results at block 808 until the threshold is reached atblock 810. Additionally, the develop parameters may be optimized inresponse to feedback from experimental verification at block 812 untilthe threshold is reached at block 814. Once the parameters have beenoptimized, they may be provided as input into the PS-CAR simulation toolat block 816.

FIG. 9 is a schematic flowchart diagram illustrating one embodiment of amethod 900 for modeling PS-CAR photoresist. In an embodiment, the method900 includes receiving PS-CAR photoresist parameter inputs at block 902and receiving PS-CAR exposure parameters at block 904. The method 900further includes computing a PS-CAR photoresist profile according to aPS-CAR photoresist profile model at block 906. At block 908, the method900 includes generating a PS-CAR photoresist profile output, in responseto the profile.

FIG. 10 is a schematic flowchart diagram illustrating one embodiment ofa method 1000 for modeling PS-CAR photoresist. In an embodiment, themethod 1000 includes receiving PS-CAR photoresist parameter inputs atblock 1002 and receiving PS-CAR exposure parameter inputs at block 1004.At block 1006, the method may include calculating a response to EUVexposure. At block 1008, the method 1000 may include calculating aresponse to a Pre-PEB diffusion step. At block 1010, the method mayinclude calculating a response to a UV flood. At block 1012, the method1000 may include calculating a response to PEB. Block 1014 may includecalculating a develop model. Block 1016 includes calculating metrologyresults. Block 1018 includes providing outputs in response to the valuescalculated in steps 1006-1016.

FIG. 11 is a schematic input/output diagram illustrating an embodimentof an input/output data set for a PS-CAR photoresist model. In anembodiment, the model may be executed by a PS-CAR simulation tool 604.Examples on inputs 1102 may include a feature layout, an exposurekernel, and EUV flare kernel, a resist parameter model, etc. In anembodiment, some or all of the input parameters may be provided by thecalibration unit 602. Examples of outputs 1104 include mask data, layoutdependent variance bands, Line End Shortening (LES), and Process Window(PW).

FIG. 12 is a schematic parameter architecture diagram illustrating oneembodiment of an input data set for a PS-CAR photoresist simulator. Inan embodiment, inputs may include PS-CAR chemistry inputs, exposureinputs, PEB inputs, etc. Examples of exposure inputs include a secondaryexposure definition, Dill C parameters, n,k parameters at secondary (UV)exposure, PS generator gradient depth, and the like. Examples of PEBinputs include parameters for: precursor, photosensitivity, diffusivity,PS generation reaction, acid quencher and neutralization. In anembodiment, Pre-PEB parameters may also be provided. Additional inputsfor continuum models and stochastic models may be provided, as well asillumination source parameters, etc.

FIG. 13 is a schematic parameter architecture diagram illustrating oneembodiment of an output data set for a PS-CAR photoresist model. In anembodiment, outputs may include a continuum model profile, stochasticmodel outputs, as well as PS-CAR photoresist-specific outputs related toPS generator profiles, and secondary exposure profiles. In a furtherembodiment, a comparative analysis may be provided indicating acomparison of the effect of PS-CAR chemistry vs. other methods.

FIG. 14 is a schematic parameter architecture diagram illustratingoperation of one embodiment of a primary exposure patterning optics unit614 of a PS-CAR photoresist model tool 604. In an embodiment, theprimary exposure patterning optics unit 614 may include multiple sets ofinputs, including mask input 1402, illumination input 1404, stack input1406, and traditional continuum resist chemistry inputs 1408. The output1410 may include an image, or data representing an image generated bythe model, that shows EUV relative intensity in either a 2D plane or a3D space.

FIG. 15 is a schematic parameter architecture diagram illustratingoperation of one embodiment of a primary exposure patterning unit 616 ofa PS-CAR photoresist modeling tool 604. In an embodiment, inputs to themodule include the EUV relative intensity data 1410, which is the outputof the primary exposure patterning optics unit 614. Additional inputsinclude continuum resist chemistry inputs 1502 and scanner inputs 1504.The EUV unit 616 may process the inputs to generate an EUV exposedlatent image 1506, or dataset representative thereof.

FIG. 16 is a schematic parameter architecture diagram illustratingoperation of one embodiment of a pre-PEB module 618 of a PS-CARphotoresist modeling tool 604. In an embodiment, inputs to the pre-PEBmodule 618 include the EUV exposed latent image 1506, which is theoutput of the primary exposure patterning unit 616. Additional inputsinclude continuum resist chemistry inputs 1602 and track inputs 1604.The Pre-PEB module 618 may process these inputs and generate a latentimage after pre-PEB 1606, or data representative thereof.

FIG. 17 is a schematic parameter architecture diagram illustratingoperation of one embodiment of a secondary optics unit 620 of a PS-CARphotoresist simulation tool 604. In an embodiment, inputs to thesecondary optics unit 620 include the latent image after pre-PEB 1606,which is the output of the pre-PEB module 618. Additional inputs mayinclude stack inputs 1702 and continuum resist chemistry inputs 1704.The secondary optics unit 620 may process these inputs and generate a UVflood relative intensity image 1706, or data representative thereof.

FIG. 18 is a schematic parameter architecture diagram illustratingoperation of one embodiment of a secondary flood unit 622 of a PS-CARphotoresist simulation tool 604. In an embodiment, inputs to thesecondary flood unit 622 include the latent image after pre-PEB 1606,which is the output of the pre-PEB module 618, as well as the UV floodrelative intensity image 1706, which is the output of the secondaryoptics unit 620. Additional inputs may include continuum resistchemistry inputs 1802 UV inputs 1804, etc. The secondary flood unit 622may generate a latent image before PEB 1806 in response to these inputs.

FIG. 19 is a schematic parameter architecture diagram illustratingoperation of one embodiment of a PEB module 624 of a PS-CAR photoresistsimulation tool 604. In an embodiment, inputs to the PEB module 624include the latent image before PEB 1806 generated by the secondaryflood unit 622. Additional inputs may include continuum resist chemistryinputs 1902 and track inputs 1904. The PEB module 624 may generate alatent image after PEB 1906 in response to these inputs.

FIG. 20 is a schematic parameter architecture diagram illustratingoperation of one embodiment of a developer module 626 of a PS-CARphotoresist simulation tool 604. In an embodiment, inputs to the developmodule 626 include the latent image after PEB 1906. Additional inputsmay include the continuum resist chemistry inputs 2002 and track inputs2004. In response to these inputs, the develop module 626 may generate afinal image after develop 2006.

FIG. 21 is a schematic parameter architecture diagram illustratingoperation of one embodiment of a metrology module 628 of a PS-CARphotoresist simulation tool 604. In an embodiment, inputs to themetrology module 628 may include the final image after develop 2006generated by the develop module 626. Additional inputs may includemetrology inputs 2102. In response to these inputs, the metrology module628 may generate PS generator parameter outputs 2104 and additionalprofile outputs 2106, including continuum parameters and stochasticparameters.

One of ordinary skill will recognize that the inputs and outputsdescribed with relation to FIGS. 14-21 are merely representative of thetypes of inputs and outputs that may be processed by the various modulesof the PS-CAR photoresist simulation tool 604. Various alternativeembodiments exist in which certain inputs or outputs are added, omitted,or modified according to model design requirements. Further, one ofordinary skill will recognize that the model may be configured to handleactual images as inputs and outputs, or alternatively, datasets. Incertain embodiments, datasets may be representative of features found inan image, or the image itself.

Persons skilled in the relevant art can appreciate that manymodifications and variations are possible in light of the aboveteaching. Persons skilled in the art will recognize various equivalentcombinations and substitutions for various components shown in thefigures. It is therefore intended that the scope of the invention belimited not by this detailed description, but rather by the claimsappended hereto.

What we claim:
 1. A method for calibrating a model of a simulatedlithography process, comprising: calibrating initial conditions for asimulation of at least one process parameter of a lithography processusing a radiation-sensitive material, wherein the radiation-sensitivematerial comprises: a first light wavelength activation threshold thatcontrols the generation of acid to a first acid concentration in theradiation-sensitive material and controls generation of photosensitizermolecules in the radiation-sensitive material; and a second lightwavelength activation threshold that can excite the photosensitizermolecules in the radiation-sensitive material that results in the acidcomprising a second acid concentration that is greater than the firstacid concentration, the second light wavelength being different from thefirst light wavelength, and performing a lithography process using thepreviously-determined at least one process parameter.
 2. The method ofclaim 1, wherein the radiation-sensitive material is a Photo-SensitizedChemically-Amplified Resist (PS-CAR) photoresist material.
 3. The methodof claim 1, further comprising receiving, at an input interface, aphysical parameter of the radiation-sensitive material.
 4. The method ofclaim 3, further comprising receiving, at an input interface, aradiation exposure parameter associated with at least one of a firstradiation source configured to emit radiation at the first lightwavelength and a second radiation source configured to emit radiation atthe second light wavelength.
 5. The method of claim 4, furthercomprising calculating, using a data processor, a profile of theradiation-sensitive material according to a lithography process model,and in response to the physical parameter and the radiation exposureparameter
 6. The method of claim 5, further comprising receiving, at aninput interface, feedback indicative of an error value corresponding toa comparison of the profile of the radiation-sensitive material and anexperimental verification of the model.
 7. The method of claim 6,further comprising optimizing, using the data processor, at least one ofthe physical parameter and the exposure parameter in response to thefeedback.
 8. The method of claim 6, further comprising optimizing anoptical parameter in response to the feedback.
 9. The method of claim 6,further comprising optimizing one or more of an acid generationparameter and a bake parameter in response to the feedback.
 10. Themethod of claim 6, further comprising optimizing a development parameterin response to the feedback.
 11. The method of claim 6, furthercomprising generating an output, at an output interface, comprising atleast one of the optimized physical parameter and the optimized exposureparameter in response to a determination that the error value is withina threshold margin of error.
 12. A system for calibrating a model of asimulated lithography process, comprising: a data processing deviceconfigured to calibrate initial conditions for a simulation of at leastone process parameter of a lithography process using aradiation-sensitive material, wherein the radiation-sensitive materialcomprises: a first light wavelength activation threshold that controlsthe generation of acid to a first acid concentration in theradiation-sensitive material and controls generation of photosensitizermolecules in the radiation-sensitive material; and a second lightwavelength activation threshold that can excite the photosensitizermolecules in the radiation-sensitive material that results in the acidcomprising a second acid concentration that is greater than the firstacid concentration, the second light wavelength being different from thefirst light wavelength,
 13. The system of claim 12, wherein theradiation-sensitive material is a Photo-Sensitized Chemically-AmplifiedResist (PS-CAR) photoresist material.
 14. The system of claim 12,further comprising an input interface configured to receive a physicalparameter of the radiation-sensitive material.
 15. The system of claim14, wherein the input interface is further configured to receive aradiation exposure parameter associated with at least one of a firstradiation source configured to emit radiation at the first lightwavelength and a second radiation source configured to emit radiation atthe second light wavelength.
 16. The system of claim 15, wherein thedata processor is further configured to calculate a profile of theradiation-sensitive material according to a lithography process model,and in response to the physical parameter and the radiation exposureparameter
 17. The system of claim 16, wherein the input interface isfurther configured to receive feedback indicative of an error valuecorresponding to a comparison of the profile of the radiation-sensitivematerial and an experimental verification of the model.
 18. The systemof claim 17, wherein the data processor is further configured tooptimize at least one of the physical parameter and the exposureparameter in response to the feedback.
 19. The system of claim 17,wherein the data processor is further configured to optimize an opticalparameter in response to the feedback.
 20. The system of claim 17,wherein the data processor is further configured to optimize one or moreof an acid generation parameter and a bake parameter in response to thefeedback.
 21. The system of claim 17, wherein the data processor isfurther configured to optimize a development parameter in response tothe feedback.
 22. The system of claim 17, further comprising an outputinterface configured to generate an output comprising at least one ofthe optimized physical parameter and the optimized exposure parameter inresponse to a determination that the error value is within a thresholdmargin of error.
 23. A method for calibrating a model of a simulatedlithography process, the method comprising: receiving, at an inputinterface, a physical parameter of a radiation-sensitive material foruse in the lithography process; receiving, at the input interface, anexposure parameter associated with at least one of a first radiationexposure step and a second radiation exposure step of the lithographyprocess; calculating, using a data processor, a profile of theradiation-sensitive material according to a lithography process model,and in response to the physical parameter and the radiation exposureparameter; receiving, at the input interface, feedback indicative of anerror value corresponding to a comparison of the profile of theradiation-sensitive material and an experimental verification of themodel; optimizing, using the data processor, at least one of thephysical parameter and the exposure parameter in response to thefeedback; and generating an output, at an output interface, comprisingat least one of the optimized physical parameter and the optimizedexposure parameter in response to a determination that the error valueis within a threshold margin of error.